Here are some possibilities:
* Biologist: This is a broad term, but most biologists study some aspect of life cycles.
* Ecologist: This scientist studies how organisms interact with their environment, including their life cycle patterns.
* Developmental biologist: This scientist studies the development of organisms from conception to adulthood.
* Entomologist: This scientist studies insects, including their complex life cycles.
* Zoologist: This scientist studies animals, and could specialize in the life cycles of specific species.
* Botanist: This scientist studies plants, including their life cycles.
* Geneticist: This scientist studies how genes influence an organism's development and life cycle.
The specific title would depend on the area of specialization and the type of organism being studied.
